Just don't use HP laptop power supplies, they get way too hot.Quote:
Originally Posted by Weezard
Even this 65w power supply next to my DV7 is keeping my sake VERY warm.
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Just don't use HP laptop power supplies, they get way too hot.Quote:
Originally Posted by Weezard
Even this 65w power supply next to my DV7 is keeping my sake VERY warm.
Anyone have a different source for those thermal pads Luxeon sells? Everything else is here or on the way other than I need to buy some wire.
I got this...SEKISUI 5760 Dbl Sided Thermal Tape
I would recommend against thermal pads, and I would use a true thermal adhesive.
Arctic Silver works great.
Have you used the thermal tape?
How does it not fall into the "true thermal adhesive" category since that is the exact reason it is manufactured?
Thermal conductivity, number one reason.Quote:
Originally Posted by mx4intx
Thermal pads/tape are notoriously bullshit, and very low TC.
I have seen it recommended for high powered LEDs in threads just like this one. More than once. This was based on the heat transfer and the fact that you can remove the led's much easier than you can with epoxy.
I also just found a thread abount the AS adhesive compared directly to thermal tape at overclockers cafe. The tape wasnt too far behind in my opinion. Especially for this application.
I guess I will just have to see for myself.
Aloha MXQuote:
Originally Posted by mx4intx
I've seen the kapton tape builds.
And I've used the thermal epoxy.
I have zero actual experience with the tape so can't condemn or promote it.
But, I can say that the stars mounted with heatsink compound and bolts do run cooler than the thermal adhesive mounts according to my "Tempgun" readings from face of the emitters.
I don't math around much, I jus' measure.:)
Pragmatism uber alles appeals to da terminally lazy!:D
As for the tape?
"Good enough" is also a working model.:cool:
Time spent agonizing over nits, is time lost growing buds, yah?
Jus' my take on it.
Aloha Y'all
Weezard
Good enough is good enough for now. I can improve it later. Nice to hear from you Weezard. When I upgrade I'll probably have to bolt them down anyway since I'll want more light and it will mean a lot more heat. I am probably going to order one more blue LED for now since the PSU will support it. That makes 5 blue 460nm, 4 660nm, and 4 625nm. I figure it might help keep the plants a bit shorter anyway since most people advise a low dense grow with LEDs.Quote:
Originally Posted by Weezard
Peace
Wow!Quote:
Originally Posted by mx4intx
That's a metric shitload of high energy light.
That ratio will make for very squat gals.
Perhaps too squat, (depending on relative efficiency of the emitters). :)
I suggest that you put a dimmer in-line with the blue string so you can trim the B:R to control the amount of stretch suppression.
I'm jus' sayin', an adjustable ratio will give you fine control and 6 amp dimmers are not expensive.:cool:
Aloha,
Weeze
If you are talking about r2 on the adjust leg I have been wondering what exactly I would need to do that.
Right now I only have 4 of the blue and 8 of the red. I just fiigured why waste the volts.
At your chosen ratio, assuming emitter efficiency of over 25%, you're looking at wanting to keep that panel way above your plants.Quote:
Originally Posted by mx4intx
I got some needlessly dense growth during veg with similar ratios, you gotta keep the light higher during veg to allow for stretch and then slam it close for dense flowering.
The dimmer should take care of that I guess and after using that for a while I will know how much of what color to add more precisely.
Anyone have any thoughts on this circuit, supposed to run LEDs off AC. Sounds useful for big high powered LED arrays. I found the circuit he referred to first.
AC-LED
10mA average from the bottom diagram, not useful for high powered arrays at all.Quote:
Originally Posted by mx4intx
Quite right!Quote:
Originally Posted by mx4intx
The dimmers I mentioned were the DC, 6 ampere, units that I used for the big light.
But, if you think about it. . .
'spose you could use a pair of 2 ohm resistors in parallel and use, say a 100 ohm, 5W. rheostat in series with one of them.
That will give a range of 1 ohm to 1.96 ohm.
That would just about halve the current when at it's max.
Thanks for suggesting trimming R2.
I probably should have done that and saved a buck or two.
Ah well, live and learn.
Aloha,
Weeze
Thats because that circuit has 20ma led's. Would have to do the math and change out most of the components to drive bigger LEDs. It's being able to do it that intrigues me.Quote:
Originally Posted by khyberkitsune
or 10ma, whatever
from that link "A larger capacitor will increase the current and a smaller one will reduce it."
Yea being able to do it is no problem. You must, absolutely must limit the reverse voltage though when powering straight from AC without a dedicated driver (just resistors and caps and a couple diodes.)
I dont think you understand the circuit.
heres another one
Circuit - AC Powered White LED Strings
Looks good on paper and I see where you are going with this.
Got some bad news for ya.:(
Just scaling up the parts falls apart fast.
A one amp emitter, or string of same uses 100 times the current of those tiny leds.
Just scaling the capacitor still up leaves huge inrush current, Vmax., and voltage spike problems.
A capacitors impedance is frequency dependant.
Higher frequency - lower impedance.
Voltage spikes sail right through them!
A tenth of a volt change is a big deal to a non-linear resistance like a led juction, and most line voltage is very far from stable or "clean".
Coupled with the peak voltage being 1.414 times the RMS voltage it becomes apparent that un-regulated AC is not a viable source for high power LEDs.
No shoot da messenger.:)
Aloha,
Weezard (electronics dick):D
Ya I didnt say it was going to be easy but it makes me go hmmm.
Quote:
Originally Posted by mx4intx
If you just must try it, here are some tips:
You need to hang a MOV, (Metal oxine varistor, and a small capacitor across the input, use a diode bridge with 4 more caps for rectification, a large electrolytic cap for DC filtering along with a tantalum cap for HF noise on the output. And a series inductor across the electrolytic to smooth the "sawtooth" ripple.
The inductor adds yet more problems at high current, so now you need "steering diodes to sink inductive spikes.
All that helps, but is still a risky supply for non-linear loads.
That can be addressed with an AC line regulator,
They are not inexpensive.:(
And without pre-regulation and transient suppression,
the complexity increases as does the parts count.:(
I found it less expensive and less worrisome to just do it right the first time.
(well, in my case, the second time):D
A DC current limit supply is the best way to drive leds.
YMCV*, but I doubt it. (*Your Mileage Could vary. You might be a very lucky person.:D)
Do it any way you wish, of course, but keep in mind, once that "magic smoke" gets out da leds are toast.:)
Aloha,
Weezard
I understand the circuit just fine, sir. I design LED and Induction lighting for a living.Quote:
Originally Posted by mx4intx
You're not understanding something.
You can't simply scale things up and expect it to work, electrical engineering simply doesn't work like that. You've barely even figured out your conductor resistances, how are you going to match the circuitry to that to avoid creating inductive loads?
Sure you MIGHT get it to work with what you're thinking but you're about guaranteed to destroy the diode in the process.
For me at least.
Cheap is mandatory.:(
Lack of Safety :blueknife: is a deal breaker.:toilet_claw:
And, Simple, unto elegance is my ultimate goal.:cool:
Easy, would be very nice as well.:rastasmoke:
This combo will usually require compromise.:)
Just think about it fo' a while.
Weeze
My conductor resistances in case of inductive loads?
An emp?
Dude, you dont design anything I think anyone who has read your posts will agree.
Weez, safe and simple is what I am looking for. I am just looking towards the future and a much larger array.
Maybe I will just see if Seoul gives away the secret in an Acriche pdf of how to run high power off AC.
Video - TinyPic - Free Image Hosting, Photo Sharing & Video HostingQuote:
Originally Posted by mx4intx
Welcome to my research facility. You do not know anything about me and I wish you would quit assuming such.
We've run the AC and DC tests, multiple times. We even made an LED T8 retrofit that runs directly off of a fluorescent ballast OR can run directly from mains voltage. BTW we were using Ariche diodes for those bars.
Guess what? 70% failure rate. We dropped Seoul Semiconductor like a rock and I am now working with Nichia to create the first true multi-band horticultural diode.
I don't design anything, such a laugh!
I have seen your video before. Like I said I read all your threads. Funny you didnt have anything to say about my conductor resistances any more?Quote:
Originally Posted by khyberkitsune
Also funny that it's "my facility" and the rest is "we have" done this and that. I doubt you are anything more than a helper. Reading your threads saying you do this and that but any time a technical question is asked you refer them to Weez or Knna or that one guy Weez helped before.
Me? I did 10 months electronic training to fix radios in the USMC. A hardcore 10 months, equal to a 2 year AA.
Calling up some Chinese manufacturer doesnt denote design and certainly hasnt helped you know what you are talking about.
This thread has so much awesome information. Thanks Weez and DH. I am reading it again...sad I know. But I read it twice and I'm still seeing new things and things I came in and asked.
Sorry if I am gunking it up last few posts.
Still waiting on the tape. Bah humbug.
When two or more conductors are in proximity to each other, altenating current in one may induce a magnetic field which will impinge on the second conductor.
Now when current builds up in a restricted area along the surface of a conductor (such as a masked trace point for soldering,) AC resistance builds up at a rate which will approach the square root of said frequency. The loss built up from the resulting AC induction will send eddy currents throughout the conductor, which can cause damage to DC-based semiconductors, such as diodes, or computer processors, as the circulating current surges through the DC component and stresses it out, thus causing early failure.
And I don't give specifics because I don't give away my designs. It's that simple.
And I've built my own HAM Radio, thank you. Even cut and wound my own quartz oscillator.
i should throw away all these full wave bridge rectifiersQuote:
Now when current builds up in a restricted area along the surface of a conductor (such as a masked trace point for soldering,)which can cause damage to DC-based semiconductors, such as diodes
Maybe the capacitor makes it a capacitive circuit? I dont know. Seems like it would be a good way to handle induction though, with the opposite. I'm going to look into it more later.Quote:
Now when current builds up in a restricted area along the surface of a conductor (such as a masked trace point for soldering,)
In the meantime I'm just going to melt a faraday cage and use that to make traces to run the AC. Should take care of that induction problem.
5k pot in parallel with 1 ohm is almost an ohm
go figger :)
the 1ohm gets all the heat right?
nm i am dumb
"In the meantime I'm just going to melt a faraday cage and use that to make traces to run the AC. Should take care of that induction problem.":S2:
I'm still trying to kindly rewind my old quartz oscillator.:rolleyes:
Cutting it to size is playing hob with my cheapie, RadioShuck, diamond saw.
And it tends to not wind, when I wind it.:error:
Maybe it's too cold.:i feel stupid:
Can I borry da loan of your Faraday furnace?:D
Seriously Khy, :wtf: are you smokin'?
I think I want some.:cool:
Aloha ya'll
Ya made me grin tonight.
Weezard
hey Weeze, if you have a minute...
http://boards.cannabis.com/attachmen...-fan-guard.jpg
That dimmer is wired on the load line of the regulator before the LEDs? Found them on ebay but the sellers arent real heavy on the specs or info.
There are different voltage models and Im not sure how they work.
Ah PWM dimmers. The 'ol on-off. Their input is the output from the, in my case, LM317? Then the output of the dimmer right to the LEDs?
PWM dimmer switch for 12v DC LED and panel lights 6 amp - eBay (item 140506143103 end time Feb-27-11 05:30:27 PST)
PWM Dimmer switch for LED lights, 12v DC
Found that. Nice price too. Specs look awesome. I'm buying one.
I'm not smoking, actually. I've been sober for the past two days.Quote:
Originally Posted by Weezard
Also, if you want a RELIABLE rectifier, rip one out of a car alternator, mx. You can't kill those things practically.